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Robert R
Robert R, ASE Certified Master
Category: Dodge
Satisfied Customers: 4538
Experience:  Dodge Master Certified, Dodge Sprinter Certified
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Intermittent cruise control malfunctions, 5.9 24v cummins.

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intermittent cruise control malfunctions
JA: Have you checked the fuse? What size is your engine?
Customer: 5.9 24v cummins. Where is fuse?
JA: What is the model/year of your Dodge?
Customer: 2000 2500 Laramie SLT
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: Yes. Checked visually for damaged vacuum line.
JA: Anything else you want the mechanic to know before I connect you?
Customer: It acts like it doesn't maintain the control and doesn't hold on hills as it did for years. It just acts like the cc is not holding where it has been set.
Customer: replied 28 days ago.
Some times it seems to work, but then just acts like it disengages and engages at a lower speed.
Customer: replied 28 days ago.
Other times it engages , but at a lower speed than where it was set at.

Hello, welcome and thanks for asking your question. My name is*****'m a Certified Auto Technician with 30+ years experience. I will do my best to assist you. please keep in mind that I may need to ask questions of you before I can answer. When you reply please feel free to add as much detailed information as possible pertaining to your concern.

There are a few possibilities for this concern. I have seen a faulty cruise control switch cause intermittent operation. Other times, I have seen the vacuum tubing wear holes in the tubing. Yet other times, I have seen the driver's side battery leak battery acid down onto the cruise control servo and either melt the vacuum hose or get into the cruise control servo and cause internal damage.

You will need to verify switch operation using a multi-meter, and visually inspect the vacuum line and cruise control servo for damage.

If you find no damage and want to diagnose the switches, let me know, you will need a multimeter and basic hand tools to run some diagnosis..

let me know if you want to perform electrical diagnosis on the cruise system ..

Thank you,


Customer: replied 28 days ago.
The switches appear to engage properly, although the pause switch doesn't always work without pushing it a couple of times.
Customer: replied 28 days ago.
Could these problems be caused by The vacuum module that controls speed?

Even though the switch "mechanically" engages, doesn't mean that it "Electrically" engages...

Yes, The Vacuum Module that controls the speed is in fact the Cruise Control Servo that I am referring to above. This part is mounted below the driver side battery. It is common for a leaking battery to cause damage to the cruise control servo... This is why I'm recommending the visual inspection.

Keep me posted...

Thank you,


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